Expression mechanism for musical instruments



C. F. STODDARD.

EXPRESSION NIEcIIANIsIvI FOR MUSICAL INSTRUMENTS.

APPLICATION FILED OCT. 3.1916. RENEWED FEB. 11,1921.

Patented Mar. 14, 1922.

@1I/Wenko@ (Va/76.5 'lfllodflarcl UNITED STATES PATENT OFFICE.

CHARLES F. STODDARD, OF NEW YORK, N. Y., ASSIGNOR T0 AMERICAN PIANO COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

EXPRESSION MECHANISM FOR MUSICAL INSTRUMENTS.

Application led October 3, 1916, Serial No. 123,464. Renewed February 11, 1921.

T0 all 'wlw/m, z'z may concern.'

Be it known that I, CHARLES F. STODDARD, a citizen of the United States, residing in the city of New York, county and State of New York, have invented an Improvement in Expression Mechanism for Musical Instruments, of which the following is a specification.

This invention relates to apparatus for automatically varying playing intensities in automatic musical instruments, such, for instance, as player-pianos and the like.

Among other objects, the invention is intended to provide apparatus capable of producing prompt changes in playing intensity while maintaining intensities so far as may be desired, regardless of the number of tones sounded. y

The character of the invention may be readily understood by reference to the accompanying drawingss wherein- Figure 1 shows diagrammatically one illustrative embodiment thereof, and

Figure 2 is a detail section on the line 2--2 of Figure 1.

In the drawings, a bellows 1 exemplifies a source of power for operating the striker' pneumatics which may be operated selectively, as well understood by those skilled in the art, from a tracker board through duets 3. A passage t connects the action chests 5 of the player actions with a port 6 into a regulating pneumatic 7 having a regulator valve 8 controlling a port 9 communicating with the source of power 1. The regulator' valve 8 is connected by a link 10 with the movable board of the regulator pneumatic 7. As well understood in the art, the valve 8 regulates the fiow of air from the action chests 5 to the source 1.

The regulator pneumatic is provided with a spring 11 fastened thereto preferably near one enol of the movable board thereof, for example, at the left in Figure 1 of the drawings. The other end of the spring may be adjustably fastened to some stationary part of the instrument so that the spring will be adapted to exert a substantially constant 'pull upon the regulator pneumatic. Tracks 14 are fastened to the underside of the movable boardof the regulator pneumatic and extend preferably from about the center thereof'to the end opposite the point of attachment of the spring 11, i. e. to the right in the drawings. A block 15, mounted to Specification of Letters Patent.

Patented Mar. 14;, 1922.

Serial No. 444,264.

slide in a stationary guideway 16, carries a pair of rollers 17 mounted upon a transversely extending shaft 1S and alapted to run in the tracks 14.

The movable board of the regulator pneumatic 7 is freely movable about the rollers 17 as a fulcrum under the control of the opposed forces of the spring 11 and the exhaust within the regulator bellows. If, therefore, the position of 'the fulcrum is changed one of the opposed forces acting upon the regulator bellows will Change as the regulating balance is maintained. The tension of the spring, with the exception of such primary adjustments as are necessary, will remain substantially constant within narrow limits, and the variable factor in maintaining the balanced condition of the regulator will therefore be the exhaust within the pneumatic 7. With the fulcrum of the regulating bellows at its greatest distancefrom the regulator spring the differential between exhaust pressure and atmospheric pressure acting upon substantially the entire area of the movable board of the regulator pneumatic, will he effective to oppose the pull of the spring. This will cause the regulator pneumatic in balanced condition to maintain the degree of exhaust within the regulator pneumatic and the wind trunk leadingL to the playing pneumatics at a point more nearly approximating atmospheric pressure. If, however, the fulcrum of the regulator pneumatic is moved toward the spring. the effective area acted upon by .the differential between the exhaust pressure and atmospheric pressure will be decreased and the spring will exert an increasing influence upon the regulation and maintain the degree of exhaust within the instrument at a lower level, that is to say, at point farther below atmospheric pressure.

The positionv of the fulcrum of the regulator pneumatic 7, which is determina-ble by the position of the rollers 17. therefore determines the regulation and the intensity of playing.

Extending from the block 15 is a rod 19 attached to the movable board of the expression bellcws 2O so that as said bellows 20 is collapsed or expanded the roller 17 will be caused to move along the tracks 14 toward or away from the center of the pneumatic 7. The pneumatic 20 is arranged to be exhausted through a duct 21'preterably having an adjustable bleed by which the capacity of the duct may be diminished so as to cause the pneumatic 20 to collapse slowlyvand thereby slowly and gradually move the tulcrnm ol the regulator pneumatic toward the left in the drawings to decrease the effective pull ot' exhaust upon the movable board ol the pneumatic 7. The effect of this, as will be readily understood by those skilled in the art, is to modify the regulation yso as to produce a gradual and slow crescendo. Then atmosphere is admitted through the duct 2l, the bellows 2() having been wholly or partially collapsed, is then expanded by a spring 22. This returns the block l5 to or toward the position shown in the drawings and thereby produces a slow diminuendo.

The bellows v20 may also be exhausted through a duct 23 of greater capacity than duet 2l to collapse the pneumatic 20 at a greater speed, but preferably the duct 28 is of such restricted capacity as to collapse the pneumatic 20 to giveV a crescendo effect similar to, but faster than that produced by exhausting through duct 2l. IVhen atmosphere is re-admitted through the duct 23 afast diminuendo results.

The pneumatic 2O may also be exhausted through a duct 24 of sullciently large capacity to permit the pneumatic to he exhausted practically instantaneously to move the block l5 rapidly toward the left in the drawings to produce a distinct step of increase in playing intensities. When atmospheie is re-admitted through the large capacity duct 24, the bellows 20 is expanded practically instantaneously to produce a dis-` tinct step of decrease in playing intensities.

To provide for a plurality of distinct steps, means are provided for'arresting the collapse of the pneumatic 20 intermediate its two extreme positions herein illustrated. Means are shown for arresting the pneumatic at one intermediate position, but obviously a plurality of such means may be provided it desired. The movable board of the expression pneumatic 20 carries at its outer end a lug 25 arranged to contact with the stop device presently to be described.

A pneumatic 26 is arranged to be exhausted through a duct 27 and is provided with a stop 28 adapted to be interposed in the path of movement of the lug 25 upon the movable board of the expression pneumatic 20, and, for example, to arrest the movement thereof when the pneumatic 20 is approximately half collapsed.

Then the stop 28 is not interposed in the path of movement of the lug 25, the expression bellows 20 will be 'completely eollapsed. If atmosphere is admitted thereto to permit expanding movement .the stop 28 may be interposed in the returning path of the lug 25 so as to arrest the expanding movement of the expression bellows 20, at approximately one hall thereof. If therea Yfter atmosphere is admitted to bellows 2G the stop 2S will be withdrawn 'lroin contact with the lug 25 by spring 29 lfast to the movable board of the pneumatic 26 and the expression bellows 2() will be permitted to expand to its full capacity.

The expression bellows 20 may thus be collapsed at any one of several speeds and to different extents to produce corresponding increases in playing intensities, and likewise the expression bellows 20 may be expanded at any one of several speeds and through different extents to produce corresponding decreases in playing intensities.

The increases or decreases in playing intensities may be by way of crescendo and diminuendo at different speeds, or may be by practically instantaneous distinct steps. All the effects described are produced in the apparatus by moving the fulcrum ot the regulator pneumatic and thereby modifying the regulation so as to produce a change in Vthe action of the regulator upon the valve 8.

The various ducts 21, 23, 24 and 27 may be controlled in any practicable manner by any suitable automatic means preferably controlled by vents in the tracker, For instance, the so-called automatic actions described in Patent No. 1,008,291 may be adapted for this purpose. These automatic actions and valves 'form in themselves no part of this invention and therefore need not be described or shown herein.

It is to be understood that this invention is not limited to the particular construction, lorganization and mode ot operation shown in the drawings and described for illustration. On the contrary, the invention may be variously embodied and the particular construction may be variously modified within the scope of the sub-joined claims. It is not indispensable that all the features of the invention be used conjointly since, in some instances, they may be used separately to advantage.

I claim as my invention:

1. In a musical instrument, the combination of playing pneumatics; a source of power for operating the playing pneumatics; a valve between said source of power and the playing pneumatics; a regulator pneumatic comprising a movable member having a fulcrum, said movable member being operatively connected to said valve; means to expand the regulating pneumatic against the action of the operating power; and means to vary the position of the fulerum of the regulating pneumatic to vary the regulation thereby.

2. In a musical instrument, the combination of playing pneumatics; a source of power for operatingthe playing pneumatics;

a valve between Said Source of ,power and sq the playing pneumatics; a regulator pneumatic comprising a movable member having a fulcrum; said movable member being operatively connected to said valve; means to expand the regulating pneumatic against the action of the operating power; an expression bellows; and means for varying the position of the fulcrum of said regulating pneumatic by the collapse of said expression bellows.

3. In a musical instrument, the combination of playing pneumatics; a source of power for operating the playing pneumatics; a valve between said source of power and the playing pneumatics; a regulator pneumatic comprising a movable member having a fulcrum, said movable member being operatively connected to said valve; means to expand the regulating pneumatic against the action of the operating power; and means for shifting the relative position of the fulcrum of said regulating pneumatic, gradually to produce a crescendo.

4. In a musical instrument, the combination of playing pneumatics; a source of power for operating the playing pneumatics; a valve between said source of power and the playing pneumatics; a regulator pneumatic comprising a movable member having a fulcrum, said movable member being operatively connected to said valve; means to eX- pand the regulating pneumatic against the action of the operating power; and means for shifting the relative position of the fulcrum of said regulating pneumatic, abruptly to produce a distinct step of change in playing intensities.

5. In a musical instrument, the combination of playing pneumatics; a source of power for operating the playing pneumatics; a valve between said source of power and the playing pneumatics; a regulator pneumatic comprising a movable member having a fulcrum, said movable member being operatively connected to said valve; means to expand the regulating pneumatic against the action of the operating power; and means for shifting the relative position of the fulcrum of said regulating pneumatic; gradually at different speeds to produce crescendos at different speeds.

6. In a musical instrument, the combination of playing pneumatics; a source of power for operating the playing pneumatics; a valve between said source of power and the playing pneumatics; a regulator pneumatic comprising a movable member having a ifulcrum, said movable member being operatively connected to said valve; means to expand the regulating pneumatic against the action of the operating power; means to shift the relative position of the fulcrum of the regulating pneumatic; and means to determine different distances through which said fulcrum may be shifted.

7. In a musical instrument, the combination of playing pneumatics; a main source of power for operating the playing pneumatics; a valve between said main source of power and the playing pneumatics; a regulating pneumatic having operative connection with said valve and means providing a movable fulcrum for said regulating pneumatic.

8. In a musical instrument, the combination of playing pneumatics; a main source of power for operating the playing pneumatics; a valve between said main source of powerand the playing pneumatics; a.

regulator pneumatic comprising a movable member having a fulcrum, said movable member being operatively connected to said valve; and means to vary the position of said ulcrum to vary the regulation thereby varying playing intensities.

In testimony whereof, I have signed my name to this specilication this twenty first day of September, 1916.

CHARLES F. STODDARD. 

